Stephen b



ii-5:55:15---:1:12:11:l.

Patented July 20V,A 1880.

s. E. BABCOGK. Smoke Stack.

yz. Q@ MW i UNITED STATES PATENT Ori-ienQ STEPHEN E. BABOOOK, `OF TROY, NEW YORK, ASSIGNOR OF SEVENTEEN TWENTY-FOURTHS OF HIS RIGHT TO I). STEVART DENNISON. JESSE B. ANTHONY, AND THEODORE E. HASLEHURST, OF SAME PLACE.

SMOKE-STACK.

SPECIFICATION forming part of Letters Patent No. 230,217, dated July 20, 1880.

Application tiled November 21, 1879,

To all whom it may concern:

Be it known that I, STEPHEN E. BABooCK, of Troy, in the county of Rensselaer and State of New York, have invented certain new and useful Improvements in Smoke Stacks, of

- which the iollowingis a full and exact description, reference being made to the accompanying drawings, making a part of this specication, in which- Figure .l is a side elevation, showing a portion ofthe outer wall removed at the line z z; Fig. 2,11 side elevation 5 Fig. 3, a horizontal section at the line x .1', and Fig. 4 a vertical section through the base of the stack at the line yy. The object of my invention is to recover the heat derived from the wasted products of combustion and absorbed by the brick-work of the chimney, and to utilize it for heating the air that is supplied to the furnaces for the purpose ot' supporting combustion; and to this end my invention consists of a smokestack constructed with a central or principal flue, for the escape of the volatile waste products of combustion, surrounded by double Walls containing air-fines, into which iines suitable inlet-openings for the admission of air are iliade near the top of the stack, and au outlet opening or openings near the base of the stack, from which the heated air may be drawn by any suitable artificial means, and then forced beneath the tires in the furnaces.

As shown in the drawings, A is the central shaft, containing the principal or smoke ue c. Said shaft may be made of any required size or form, and connected with the furnace for which it is intended in any suitable manner. An outer wall, B, entirely surrounds the shaft A, and is placed at sufficient distance therefrom to form theair-iiues b, which inclose the central shaft. Said air-fines I preferably divide by means of the vertical partitions b and horizontal partitions b2, for the purpose of preventing the air in said iiues from reaching the exit by the shortest course thereto.

Inlet-openings C are made through the wall B at each side of the chimney, near the top thereof. Said openings communicate directly with the air-lues b, and through these open- I the fan.

ings the said tlues are furnished with asupply of air from the surrounding atmosphere.

Au outlet-opening, I),is made near the base ofthe chimney through the outer wall, B. Ali of the air-fines I), at their lower ends, have a direct communication with the said outletopening, to which an exhausting apparatus must be attached for the purpose of drawing down ward the heated air from out the air-tlues in opposition to its natural tendency to rise.

The exhausting apparatus (shown in Fig. 1) consists of a fan-blower. E, whoseinduction- 6o pipe e is connected directly to the outlet-opening D of the chimney, and forms a communication between said opening and the center of The eductlon-pipe c oft-he fan-blower conveys the heated air drawn out ot' the air- 65 iiues by the fan-blower beneath the furnacetires in the usual'inanner.

In smoke stacks ofthe ordinary construction the heat absorbed by the4 brick-work is not only entirely lost for any useful purpose, but 7o it is also very destructive in its effect on the masonry. A

The central shaft, A, of my chimney becomes heated by absorbing the waste heat from the furnaces; and if this heat can be utilized in the 7 5 manner hereinbefore described I derive the benefit ofthe Well-known fact in caloritics that every unit of heat imparted to the air supplied for supporting combustion produces a corresponding saving in the amount of fuel required 8c in the furnaces, and it follows that if the heat absorbed by the chimney can be taken up and recovered by the air for supplying the furnaces a saving' of fuel will be effected that will equal the amount required for increasing the temperature'of the atmosphere to that of the air so heated. To produce this effect the airis drawn from the lower end'of the air-tlues b by the eX- hausting apparatus connected to the outletopening D, anda partial vacuum is thereby 9o created in the air-fines, which are instantly refilled by the air entering the inlet-openings O.

In this manner a constant iiow of descending currents of air, as indicated by the arrows in Fin'. l, is established in the air-iiues, and these 95 currents take up the heat radiated from the masonry, and the air is thereby reduced to a highly-heated condition before it is discharged from the eduction-pipe of the exhausting apparatus, by which it is conveyed beneath the ires in the furnaces.

By taking the cold air in at the. iop ot' the chimney it is brought into contact, while in its coldest condition, with the coolest part of the central shaft, and as the air descends it progressively comes in contact with the parts ot' the shat't Where the heat is constantly increasing, until it reaches the hottest part at the hase, where the air is drawn out, as before described, in its most favorable condition for supplying the furnaces.

By means of the partitions b and b2 the aircurrents are prevented from pursuing the shortest course to the outlet-opening D, and arel therefore kept longer in contact With the heated masonry, and the central shaft and outer wall of the chimney are by these partitions bonded together to produce greater strength in the structure.

I am aware that smoke-stacks have heretofore been constructed with an inner and outer shell arranged to leave an annular space between them, the. air being' admitted into said annular space near the top of the stack and drawn out by means of a fan through exitopenings near its bottom; but such a construction fails to utilize but a small portion of the waste heat, for the reason that theannular space being undivided by vertical partitionsinto separate air-iiues, the air entering the inletopenings at the top of the stack will be drawn by the fan in the most direct line to the exitopenings, and bypassing obliquely from the inlet to the outlet openings will only be brought into contact with a small portion of the heated inside flue. y

Smoke-stacks have also been constructed with inside and outside shells, and having the intermediate space divided into cold and hot air iues, the air being admitted, near the bottom of the stack, into the cold-air lues, through which it passes upward to the top of the stack, and from thence downward through the hot-air flues to vthe exit-openings at the bottom ot' the stack; but in that construction the action is so sluggish th at provision is made for stimulating it by forcing the air upward through the cold-air ues by means of the exhausting-fan.

I claim as my inventionl. As animproved smoke-stack, the construction herein described, consisting ot' the central shaft, A, outer Wall, B, and air-ues b, said iues heilig formed by the partitions b and b2, and having inlet air-olienings C near the top of the stack, and outlet-opening D near the base thereof', as and for the purpose herein specified.

2. The central shaft, A, outer wall, B, andpan titions b b2, arranged, as herein described, to form the air-iiues b, the inlet-olrienings C, and outlet-opening D, constructed, arranged, and combined with an exhausting apparatus, as and for the purpose herein specified.

STEPHEN E. BABGOCK.

\V i tnesses WILLIAM H. Low, D. H. HUMPHREY. 

